Apparatus for admixing liquid components in a predetermined proportion (ratio) are known, especially in the carbonated beverage industry. Some of these apparatus provide various liquid components to a mixing chamber from either supply conduits or supply vessels. Each supply conduit or vessel is associated with a separate pump that draws the liquid component from the conduit or vessel and introduces it into the mixing chamber. The various liquid components are admixed together in the mixing chamber and the resulting admixture can be delivered therefrom to other processing stations such as bottling stations. Unfortunately, such apparatus are complicated in that they require an individual pump to be associated with each supply conduit or vessel Furthermore, variations in the pumping capacity, which can be caused by fluctuations in the electrical current supply, different liquid flow conditions or the like, can cause substantial variations in the ratio of the liquid components in the admixture which is highly undesirable.
Another known apparatus provides a mixing chamber into which the supply conduits discharge the various liquid components to be admixed. The admixture is discharged from the mixing chamber through a discharge conduit. Control devices are provided in the mixing chamber which are operably associated with valves provided in the supply conduits to regulate the quantity of liquid components that can flow into the mixing chamber from the respective conduits. When the mixing chamber is filled these devices control the discharge of the resulting admixture by means of a pump. Unfortunately, for each different ratio of liquid components, a separate control device must be provided. Thus, when the ratio is to be changed the control devices must be changed which is not only time-consuming but also is expensive in terms of down time of the apparatus, labor required to make the change and the necessity to keep a variety of different control devices on hand.
U.S. Pat. No. 3,743,141 to Mnilk et al. discloses a mixing apparatus for liquids that includes supply vessels that contain the liquid components to be mixed. The liquid components are supplied to the mixing chamber via gravity feed and throttling devices. Thus, the ratio of the liquid components achieved using this apparatus is dependent upon not only gravity but the hydrostatic head in the supply vessels that can change as liquid component is supplied thereto or removed therefrom. That is, the amount and weight of the liquid component in the vessels and the height the vessels are above the throttling device affect the ratio of the liquid component. Such a system is difficult to control. Furthermore, if the viscosities of the liquid components differ by a large amount additional difficulties can arise in obtaining the proper ratio.
U.S. Pat. No. 4,669,496 to Kemp et al. discloses a liquid proportioner having a water chamber and a syrup chamber in communication with a mixing chamber from which the combined liquid is displaced to a tank. The water and syrup chambers are pressurized with a gas to force the fluids into the mixing chamber and thereby into the tank. The pressure in the tank is relatively high. Therefore, the pressure within the water, syrup, and mix chambers must be higher than the pressure within the tank into which the combined liquid flows. Thus, the entire proportioner of Kemp operates at a relatively high pressure and uses a high pressure gas source. This proportioner undesirably requires the use of relatively expensive chambers, conduits and the like capable of withstanding the elevated pressure. Furthermore, the use of high pressure gas can be dangerous in the event of a leak.
Cleanliness is important because the mixture is consumed by people and therefore sanitary conditions must be maintained. Conventionally, baffles are welded in the chambers to assist in maintaining a nonturbulent condition therein. Unfortunately, the baffles, they cannot be removed, making cleaning of the baffles and chambers more difficult. Also, the weld itself is difficult to clean.
Often, supply vessels cannot be completely drained of liquid during normal production of the beverage and the liquid must be discarded. While discarding the liquid is not a problem when the liquid is water it is a problem when the liquid is a flavored liquid (syrup) used in the production of the beverage. Not only is there an economic cost in the waste of the flavored liquid but there is also an environmental cost as the discarded flavored liquid can enter a water way through the plant's sewer system and result in an unacceptably high biological oxygen demand (BOD) due in part to the sugar content of the flavored liquid. Too high of a BOD can adversely affect the ecosystem. If the sewerage from the plant is treated by a municipal sewage treatment plant the unacceptably high BOD can increase the fee the plant is charged for sewage treatment.
U.S. Pat. No. 4,944,601 to Damon discloses a syrup recovery system to permit recovery of residual fluid after a normal production run and reduce the introduction of a large quantity of sugar to a bottling plant's sewage system. Unfortunately, the system taught by the Damon patent requires the bypassing of the mixing manifold used in normal production runs resulting in mixing occurring in a different way than in normal production. The system also requires the creation of a venturi effect to draw the syrup out of the syrup reservoir which is a different way of removing the syrup than occurs in normal production and which can result in an uneven flow of syrup due to variations in the venturi effect.
A proportioner apparatus and method capable of admixing liquids in an accurate ratio, at relatively low pressures and that minimizes waste of the flavored liquid is desired especially in the beverage industry. The proportioning apparatus of the present invention satisfies at least some of these desires.